Polyisonitriles. II. Heterophasic catalytic synthesis of poly(α‐phenylethylisonitrile) and of poly(n‐hexylisonitrile)

A three‐component catalytic system has been discovered, which successfully polymerizes α‐phenylethylisonitrile to high polymer (DP = 200–900) and also polymerizes n ‐hexylisonitrile. The catalyst components are a strong acid, a free‐radical source, and a heterophase and are all necessary in this system. The use of a liquid medium in which the polymer is insoluble promotes the rate of polymerization and total yield. Poly(α‐phenylethylisonitrile), formed from monomer in a presence of oxygen and finely ground glass coated with sulfuric acid, can itself serve, in the presence of monomer and oxygen, as a catalyst for this polymerization. Preparative details and discussion of these synthesis factors are given.